Jack



June 16, 1925.

M. L. HEINEKE Filed May 12; 1924 3 Sheets-$heet v1 A TTORNEYS,

Jun 16,1925. I 1,542,132

,M. L. HEINEKE JACK Filed May 12. 1924 3 SheetSSheet 2 A TTORNEYS June -16, 1925. 1,542,132

- M.'L. HEINEKE JACK Filed May 12. 1924 3 Sheets Sheet 5 Fl .7. M 3

moi, kw-

WMflMw ATTORNEYS,

Patented June 16, 1925,

UNITED STATES PATENT OFFICE.

JACK.

Application filed. May 12,

T cll'wimm it may concern:

Be it known that I, MARTTN L'HELNEKE, a citizen of the United States, residing at. tij iringfield, countyof Sangamon, and State of Illinois, have invented new and useful Improvements in Jacks, of which the following is a specification. p

This invention relates to improvements in jacks. More specifically, this invention relates to wheeled jacks of the type adapted for garage use;

It is the. primary object of this invention to provide a novel and improved jack of the distant control type, wherein each forward and each backstroke of the handle will. serve to elevate or lower alifting member at a distance therefrom. In many jacks of this general type'whieh have heretofore been designed the arrangement has been such that the handle operates to lift or lower the jack memberonly when it is moved in one direction. The return strokeQof the handle accomplishes no useful purpose, and consequently, the mechanical advantage of such a jack, considering every handle movement, is comparatively low.= It has been my purpose in developingthe ack disclosed herein to provide a construction such that despite the distance between the handle and the jack member there will nevertheless be provided means'for utilizing every movement of the handle for actively lifting or lowering the load. Thus, I am able to lift a load with my improved jack in less time, with less effort, with fewer strokes, and with greater jack where a unidirectional stroke is operative forlifting purposes.

It will be understood those skilled in the art that in the type of. jack to which this invention particularly relates, i. e., in a jack in which the lifting member or plunger is located at one end of an elongated frame and the handle is located at a distant limit; onsaid frame, it is comparatively difticult to work out what may be termed a double acting aelt movement. It would be less diliicult merely to provide a double acting; jack of this type to move the load in one direction only, but it is my purpose in the present inventionto providc mcans for utilizing every stroke of the jack handle to move the load, whether thejaek is adjusted for lifting or forlowermg. Consequently,

1 924. Serial No. 712,567.

it an important feature of this invention to provide simple, effective and novel means for controlling the movements of the load carrying element sothat upon the oscillation of the jack handle the load carrying element may readily be caused either to lift or to lower the weight carried thereby as the operator may desire While it is my broad purpose to-provide a double acting jack as aforesaid, it is also my purpose to provide an improved set of motion transmitting connections between an oscillatory jack handle and a load lifting element. Such motion transmitting con nections as those hereinafter to be disclosed are adapted for use in single acting jacks as. well as in double acting jacks, and consequently, I will hereinafter disclose the ap plication of these motion transmitting connections to both types of jack.

Other objects of this invention are to provide an unusually sturdy and simple type of jack mechanism having comparatively few parts to provide a ack with novel and simplified means for obtaining a preliminary adjustment of the load carrying elen'lent; to provide a jack which can. be easily and cheaply manufactured and readily operated by unskilled persons without danger either to the jack or to the vehicles manipulated therewith.

In the drawings:

Figure 1 is a plan view of the jack embodying this invention, the jack frame bejinp; foreshortened and the handle cut away. mechanical advantage than is possible in a Figure 2 is 'a side elevation of thedevice shown in Figure 1, with the side of the jack frame partially removed to expose the mo tion transmitting connections.

Figure is an enlarged detail view taken on the section indicated at 33 in Figure 2.

Figure 4- is a detail view of portions of the motion transmitting" connections shown in Figure fz. illustrating the parts in one position which they will assume when the jack is in operation.

l igure 5 aview similar to Figure 4;, showing; the same parts in different rela ti positions.

,Figure 6 is a further view similar to Figure dcshowing the parts in a further set of relative positions.

Figure 7 is a fragmentary plan viewof a' single acting jack embodying portions of this invention.

Figure 8 is a detail view in side elevation of the motion transmitting mechanism shown in plan in Figure 7.

Figure 9 is a View similar to Figure 8, showing some of the same parts in different relative positions,

Figure 10 is a further view similar to Figure 8 and showing some of the same parts in further different relative positions.

Lilte parts are identified by the same reference characters throughout the several views. I

The jack frame includes a cylinder casting it) in which is vertically movable a plunger or load carrying element 11 having a. telescopically adjustable portion 12 with a load carrying head 13. The cylinder casting 10 may be supported in any desired manner but is preferably provided integrally with an axle 1st offset forwardly from it and supporting it from wheels 15.

It is the function of member 12 merely to provide for a preliminary adjustment in height of the load carrying element. For this purpose the member 12 is preferably peripherally grooved as at 18. In order ad justahly to support telescopic member 12 with reference to the main plunger or load carrying element 11, I may utilize a box 19 connected with member 11 and containing a slide 20 having an arcuate notch adapting it to fit about the reduced diameter of member 12 within one of the peripheral grooves 18 of said member. Thereby the telescopically adjustable parts 11 and 1.2 are maintained positively the desired position of adjustment and, at the time the mem ber 12 is free to rotate upon the supporting slide 20.

When it is desired to changed the adjustment of these parts the operator may grasp the head of a rod 22 connected with a slide 20 and may thereby retract the slide against the compression of spring 23. As SOODHS the slide clears groove 18 it will be possible to lift or lower member 12 manually with respect to member 11.. When, however, the head 21 is released by the operator, the slide 20 will again be forced by spring 23 into one of the peripheral grooves 18 of member 12 to restrict members 11 and 12 against relative vertical movement in any position of adjustment of these members so that they are operated as one by the lifting and lowering mechanism hereinafter to be described. In the lifting and lowering of the plunger or load carrying element 11 the said element is guided within the cylinder 10. It prefer ably has a rather close tit in the cylinder. For a similar purpose the ungrooved portions of member 12 will also preferablyhave a rather close fit within the hollow piston or load carrying element.

Connected with the cylinder casting 1H and evtending rearwardly therefrom are laterally spaced parallel bars 25 and 26. These bars comprise the frame of the machine but it is immaterial to this invention whether m not the elongated frame be constructed in the specific manner herein disclosed. The rear end of the frame is supported by a caster wheel 27 in order that it may be rcadil manipulated from side to side under load. Immediately above the caster wneel 2? is an upwardly extending handle 30 which is escillatory on bolt 28 as a fulcrum, whereby to serve as a lever for the lifting and loof loads. The handle serves also to enab e the operator readily to manipulate the entire jack upon its wheels 15 and 27.

A connecting rod 31 is pivoted to (he handle 30 at 32 and extends forwardly there-- from between the parallel sides and 26 of the frame. The connecting rod is made fast at its forward end to a slide 34 which is slotted at 35 for guidance upon a transverse shaft 36. Upon this shaft is mounted a toothed wheel 37 to which is pivoted at a link 39, the other end of which is pivotally connected at 41-0 with the load carrying element 11. The link may conveniently be double as is best shown in Figures 1 and 3, to engage each end of pin 40. Pin 40 intermediate the two link members 39 passes through an car 41 projecting laterally from the member 11 which it actuates. Obviously, if the toothed wheel 37 be rotated clockwise from the position in which it is illustrated in Fig;- ure its movement will be transmitted through links 39 to the load carrying: element to elevate said element. conversely. a counter-clockwise rotation of the toothed wheel 37 toward the position in which it anvears in'Figure 2 will lower the load can, ing element.

Means will now be described for utilix nft' reciprocatory movement of connecting rod 31 and slide 34; to control the rotative movement of the toothed wheel 37.

For the purpose of securing such control the slide 34: carries a pair of dogs 11?) and l which are pivoted thereto at 4'5 and 46. respectively. These dogs are provided with pointed extremities engageal'ile with the teeth of wheel 37. The extremity -17 of dog 43 is in the form of a hook and engages the teeth of wheel 37 in the manner of a hoo f. The extremity 48 of dog 4.4: is formed like a finger and engages the wheel 37 with a push ing action. Consequently. dogs 43 and 4' t will hereinafter be termed, respectively,tension and compression dogs.

Since 02 ch of the aforcmentioned dogs is pivoted within the central slot of slide 34:. it will be obvious that as such slide is reciprocated by the oscillation of handle 30 the dogs 4-3 and 14: will be reciprocated therewith.

Int-he course of such reciprocation the dogs will be caused to'move to and fro with re spect to the teeth of wheel 37 and, it the dogs continuously follow the contours of such teeth, theirreciprocation will obviously result in producing ZLClOClUVlSB rotation of wheel37 to produce a lifting movement of the load carrying element 11. To ensure that thedogs will thus follow the contours of the teeth when desired I provide a compression spring; 49 confined between the rear ex remities of dogs 43 and 44' to force such extremities apart and thereby to keep the for *a-rd ends 47 and 4:8 of'the dogsin contact with the wheeh except at such times as other meanshereinafter to be described are acting upon the dogs.

lt willbe observed from the foregoing that the lifting operation ofthe jack is accomplished by a substantially pure ratchet and pawl movement. "VVhen, lior example, handle is oscillated counter-clockwise the eonnectingrod 3i and slidefle will be reciprocated to the right as viewed in Figure 2. Thereupon thepoint 4-7 ofdog 43 will pull rearwardly upon the tooth of wheel 37 with which it engaged, thereby causing the said wheel to rotate clockwise. At the same time the point 48 of dog 414;, in. moving rearwardly, will ride over the tooth which it abuts and will engage behind said tooth to support the wheel 37 against counter-clockwise rotation.

As handle 30 reaches the extremity o'tits oscillatory stroke and is 'lJlOJQCl clockwise, theslide 3st willhave a corresponding moren'ient tdthedl't, as viewed in Fi 'ure 2.

lilooloshaped extremity 4-7 otpawl will ride over a tooth of wheel S'Twhilethe. tin gerlike end &8 of pan '1 {1-4: is engaged with a, tooth on the lower side of saidwheel and,

due to its eu eagei'l'ienttherewith, pnsl'iing these-id tooth to the left and continuing the cloclr ise rotation of the wheel. When itisdesired to lower the load carrying element a special pawl-controlling mechanism is broughtdnto service, lhis mechanism is adjusted any desired inanner, such for examplelas bythe provision of a level- 50 on the jack frame; ilhi's lever is carried by ashort shaft 51. ext ending' transversely through the side member 26 of the frame, andcarrying on its inner end a cranharni and crank pin 52. 'A link connects the crank pin with a cross head M slidable upon the frame member 26 longitudinally "of the frame. Arms '55 and 56 pivoted to the cross head 5a externally ol' the frame member 26 carry pins 57 and 58, respecti'vcly which ride on the upper and lower margins of frame member 26 or are otherwise longitudinally guided with reference to said frame member-RA tension spring" .59 connecting arms and 56 keeps the pins 57 and 58 normally 1n contact with ited in such movement by stops 62 the margins of the frame member fill The length of pins 57 and 58 is such that they project into the tooth ot the rearward extremities 60 and 61 of dogs 4-?) and 41:41, re spectively. i

The handle 50 has an ()SUilltihOl')"lI]0\%- ment on theaxis ot the shattbl and is li1n and 63 carried by the frame element 26. lVith the handle 50 in the position in which it is illus trated in Figure 2 (in contact with stop 62) the cross head 54- is in its extreme position to the right, and the arms and 56 have been retracted to such a point that the pins 57 and 558 are not operative with respect to dogs 43 and 44. In this position the dogs will operate as'pawls to elevate the load carryingelement 11 in the manner already described. It, however the handle 50 be oscillated to the position in which it appears in Figure 1, the cross head 54 will move to an extreme position at'the left and the pins 5'? and 58 Will b8 moved into operative association with the peculiarly termed cam surfaces at therear extremities 60 and 61 of dogs 43 and 4st.

In the above described relation of the parts every oscillatory movement oli handle 30 will result in lowering the load carrying element of the jack. In Figure 4: the parts are shown as theyappear when the handle 30 is oscillated forwardly to retract slide 34., and the dogs 4:3 and l-el carried thereby. The strength oi tension spring 59 isnnderstood to besuch as to overcome the strength ol? compression spring 419. Inasn'iucln how ((311115 the pin 5"is engaged in the lowest purt o1 the ca'i'ndilre depression in the rear es ren'iity'ol dog 12:3, it will be obrious that the compression oi? pring all) will be freely exe ted to maintain the hook portion fl-.7 of by engagement with a teeth of wheel Pinfitl, on the other hand, \i'illhave ridden onto a relatively high portion of the cam (lop; =14 and will thereby surface or have forced the said dog outwardly away from the teeth'ot' wheel As the handle 30 moves rearwardly the parts will assume the positions illus rated in Figure 5 wherein the 1,-elati\"ely stationary pin 5? is riding onto the elevated cam surface oi? dog 413. At the same time pin has, due to the -forward nltidtfil'lel'li of dog illpassed downwardly from the h igh. portion of the cam surface on. said dog and is permitting said dog to be forced by the compression of spring 11-) into engagement with a next succeeding toothon wheel .As the rearward movement of the handle continues, the parts reach the position in which they are shown in Figure 6, wherein the finger portion 48 of dog M is in full engagement with the next succeeding tooth lilt) slide 3i and dogs 43 and H are moved rearwardly, the dog l t-carrying the load until dog 43 reaches the next succeeding tooth in a position corresponding to that of Figure land picks up the load. During thisirear ward movement of the-parts the finger portion 4:8 is heldby the loadin engagement between two adjacent teeth of wheel 37 despite the action of pinIiS, which tends to force thedog outwardly to the Figure 41- position thereof. Consequently,the pin is forced to yield on arm '56 against .the tension of spring 5.). As long, however, as the hook portion 47 'of dogs-3 takes up the load as shown in Figure 4; the saiddog l l springs outwardly'to its Figure lposition and, due to the cam action of pin 58 upon it (it will, during the next rearward oscil lation of the handle, pass over the teeth which it has previously supported and-will engage the next succeeding tooth. .This action is continued until dog a l reaches the last tooth of the series with which wheel 37 is provided, or until handle 50 is oscillated to retractcross head 54 and the pins 57 and 58 connected therewith. V

Figures 7 to 10 illustrate a single acting jack in which the jack lever is operative in but one direction of movement to lift or to lower the load sup-porting element. These views show the parts from the oppositeside from which they were disclosed in the pre ceding views. The frame members 25 and 26 may correspond exactly with views previously described. So also the cylinder casting 10 and load carrying element 11 may correspond with the similar .parts on the double acting jack. The load ca-rryingelement 11 is preferably connected with the toothed wheel 37 by the same vtype'of link 39 used in the jack previously described.

In the single acting jack. however, there is but one reciprocabledog. This dog is carried by a slide 34 connected by red 31 withthe handle. whereby it maybe caused to reciprocate. The single dog 43 which is carried by slide 34% is preferably substantial-- ly .indentical with that already described. The other dog comprises purely a pawl having a finger portion 418 and. an arm 66 projecting rearwardly-beyond its cam surface 61. The arm 66 receivesthe pressure of a. relatively fixed compression spring 67 whereby the finger portion 48 of the pawl 65 is normally maintained in contact with wheel 37. With theparts as shown in Figure 10, the jack is set; for. alifting operation, and upon each oscillation of-the controlling hanthe 30,. as-previously described, the slide 34 willbe-caused to reciprocate and the single dog 4.3 carried therebywill alternately engage one ofthe teethof wheel 37 on its rearwardstroke. and-will ratchet over the next adjacent tooth on its forward stroke. Vhen the dog-43 is ratcheting over a teeth of the wheel, the point ofpawl-GS will be opera tive to prevent any retrogressive movement onthe wheel.

:If the cross-head (i l be now' adjusted to the-position in which it appears in views 7, 8, and 9 of the. drawing thetransverse pin 69 carried by. arm 70. pivotedto the crosshead will bemoved-forwardly along the side member 26 of the frame. Lt-willbe guided with reference to said side member by means of the tension spring 71 which holds it thereagainst. In the course of the forward movement ofpin 69 the said pin-will ride upon an elevated -cam surface of dog l3 and will thereby lift the hook portion 47 of said dog clear of the toothed wheel 37. -At the sameti-me the pin- 69 will operate with a certain degree of lost motion upon the extremity of a slottedlink 72 which controls the position of cam 73. During the lifting operation the-said cam 7 3 was operative, as shown in Figure 10., to force out of the path of" pawl 65 the pawl-controlling lever 74 and pin 75. against the tension of spring 76. lVhen, however, the cross-head 54 is moved forwardly to its new position it permits .the spring 76 to oscillate lever 74in a clockwise direction to push cam 73 to the position in. which it appears in FiguresS and 9. The lost motion provided by theslot in link 7 .3 allows the cam 73 to retain this position despite the movement of. the slide 34- upon which it is mounted.

With the parts as shown in Figure 8 the .entire weight or load on element 11 is supported by the pawl 65. As the actuating handle is moved forwardly the dog 43 is imparted a corresponding rearward movement. and its hooked extremity 47 ultimately picks up a tooth of wheel 37, thereby relieving the finger 48 or pointof pawl 65. 'The pin 'carried by lever 74 will, in the course of this movement, have moved onto the relatively higher cam surface of pawl 65,'thereby moving pin 75 out of contact with the lower surface of side member 26 of'the frame andplacing a resulting adkeeps the point of the pawl in engagement between two adjacent teeth of the wheel. \Vhen, however, the hook 47 picks up a tooth of said wheel and relieves pawl 65 of loadythe said pawl springs outwardly as .shown inv Figure 9. v As the actuating hanlUQ presses the rear end of dog 43, as shown in lligure 8,-whereupon the operation is repeated to lower the load supporting element as long as the handle 30 is oscillated or until the last tooth of wheel 37 is reached,

or the cross-head Set is adjusted for upward movement.

While the construction illustrated in Fignres 1 to 6 is very much. preferred by me, nevertheless it will be recognized by those skilled in the art that the double and single acting jacks herein disclosed have much in common and each satisfies in some measure the objects of this invention. In this regard the double acting jack'obviously comes closest to completely satisfying my purposes since, its use in actual tests has demonstrated the fact that it will act easily to raise greater loads in less time than can be raised with any ack of like type with which I am familiar. This is: accomplished due to the fact thatlhavesucceeded in producing in this type of jack a motion transmitting mechanism such that each forward and back stroke of the actuating handle results in movement of the load supporting element.

I claim:

1.. In a device of the character described, the combination with ahorizontal frame and an oscillatory handlecarried thereby, of a load supporting element vertically movable with reference to a portion of said frame longitudinally spaced from saidhandle, and motion transmitting connections operative between said handle and said ele-.

ment and adapted to actuate said element in a given direction upon the oscillation of said handle in either-direction,

2. In a device of the charac ter described, the combination with a horizontal frame an oscillatory handle mounted thereon and a vertically movable load supporting element connected with the frame at a point remote from the handle, of motion transmitting connections operative between said handle and said element to actuate said element uni-directionally upon each movement of said handle 1n either direction, and means for controlling said motion transmitting connections, whereby said connections will selectively actuate said element either upwardly or downwardly.

in a device of the character described,

the combination with a vertically movable load supporting element, of a rotor journalled adjacent said element upon an axis transverse with respect to the path of movement of the element,and a link pivotally coimected with both said rotor and said element, whereby to transmit vertical movement to said element upon the rotation of said rotor.

4:. In a device of the character described, the combination with a. load supporting elee ment guided. for vertical movement of a link pivotally connected with said element to swing in a plane substantially parallel to the path of said movement and substantially radial with respect to said element, and a toothed wheel journalled for rotation adj acent said element in a plane substantially parallel to said first mentioned plane and having a portion operatively connected pivotally with said link.

5,111 a device of the character described, the combination with a vertically movable load supporting element, of a rotor jour nailed for operation adjacent said element and provided with a plurality of teeth having their corresponding sides substantially disposed respectively on radii and chords of said rotor, a link operatively connecting said rotor with said element, a slide reciprocable adjacent said rotor, and dogs operatively connected with said slide and positioned forengagement with the said teeth alter nately at substai'itially diametrically op-- posite sides of said rotor, whereby to trans mil: rotative motion to said rotor upon the reciprocation of said slide in either direction. v v

6. In a device of the character described, the combination with a pair of members guided respectively for reciprocal movement substantially at right angles to each other,

of a rotor disposed adjacent the point of intersection of the paths of movement of said members, means adapted to transmit motion to said rotor from one of said members to produce uni-directional rotation of said rotor upon the movement of saidmemher in either direction of reciprocation, said rotor being directly connected with theother-fof said members, whereby the reciprocative n'lovement of the first of said members will result in uni-directional movement of the other of saidmembers.

'7. In a device of the character described, the combination with a pair of members guided for independent reciprocation in angularly related paths of movement, of a toothed rotor adjacent the point of intersection of said paths of movement of said members and directly connected with one of said members, and a set of dogs movable with the other of said members and adapted to engage mutually remote teeth on the periphery ot said rotor, said dogs being ion lll)

[Ill

adapted to produce uni-directional rotation of said rotor upon the reciprocation in either direction of the member with which the dogs are movable;

8. Ina device of the character described, the combination with a pair of members guided for independent reciprocation in angularlyrelated paths of movement, of a toothed rotor adjacent the point of intersection of said paths of movement of said members and directly connected with one of said members, and-a set ofdogs movable with the other of said members andadapted to engage mutually remote -teeth on the .peripheryot said rotor, said dogs being adapted to produce uni-directional rotation of-said rotor upon the reciprocation in either direction of the member with which the dogs.

are movable,-and means operative to control said dogs during the reciprocative movement of the member by which they are carried, said means being adaptedselectively to control the direction of rotation of said rotor, and the consequent direction of re-- bers movable in angularly related paths, of-

a toothed wheel disposed adjacent the point 01" intersection between said paths, a link pivotedto said .wheel and to one of said members, and a dog connected with the other of said members for movement therewithand adapted for interaction with succes sive teeth on said wheel/ 11. The combination with a frame and a load supporting) element suitably guided therein of a rotor adjacent said element andconnected therewith, a handle pivotally con-- nected with said frame at a distance from said element and saidrotorand oscillatory through an are above its pivotal connection, and motion transmitting connections between said handle and said rotor, said con-- -nections beingadapted to produce unidirectional movement of said rotor upon oscillation of thehaudle in either direction.

12. In a device of the character described, the combination with a vertically reciprocable load supporting; element, of a frame providing a guiding channel for said element, an ear projecting laterally from said element, a rotor journalledi in said frame adjacent said element and substantially in the plane of movement thereof,

and a link comprising spaced members pivotally conneetedwith said ear and said rotor upon either side thereof.

13. In "a device of the character described, the combination with the spaced side members of a jack frame, of a transverse shat't supported from-said members, a rotor journaletl on said shaft, a slide comprising laterallyspaced members disposed between said frame members and guided upon said shait upon either side of said rotor, and dogs pivotally connected between the laterally spaced members of said slide and extendedrespectively above and below said rotor for interaction therewith.

M. In a device of the character described, the combination with a jack frame and a toothed wheel-journaled therein, 01 a slide guided for reciprocation in said frame, and a pair of dogs adapted respectively for en gagenie'nt witlrthe teeth on the upper and lower portions of the periphery oi said wheel, oneofsaid dogs being provided terminally with a hook member-and the other bein-g 'a compressionmember adapted to transmit motion to said wheel-to cause unidirectional rotation thereot upon movement of said slide in eitherdirect-ion.

15. In a device of the cliaracter-described, the con'ibination witha jack frame and a toothcdwvhcel journaled therein, of a slide reciprocable longitudinally of said, frame to and from said wheel, tension and compression dogs pivotally connected with said. slide to move relative thereto and engage able respectively with teeth at spaced'portions on the periphery-of said wheel, a springurgingthe'.terminal portions of said dogs toward position to engage with said teet-h'as the slide reciprocates, and means selectively operative in the path of movement -oi said dogs with the slide to trip said dogs at predeterminedpoints in said path, whereby to permit said wheel to rotate reverselyat a predetermined rate during the reciprocation of said slide.

16. Ina device oi the character described, the combination with a load supporting element-and a toothed wheeloperatively connected therewith to reciprocate said elements in accordance: with the rotation oi said'wheel, of av slide guided for reciprocation- \vithrespect to -said wheel, dogs piv otally connectedwith said-slide and having a terminal portions formed for engagement with the teeth oi said wheel'at-spaced points on the periphery thereotya spring urging; said'terminal portions in the direction oi said wheel, a pair ofdog-tripping elements manual-i adjustable to and from operative position with respect to the path of movement oi said dogs, and cam meansconnected with said dog's andaidapted for interaction with said elements when said elements are in their-said operative position, said cam the combination with a vertically reciprocable load-carrying element and a toothed wheel directly connected therewith, the periphery of said Wheel being formed with surfaces disposed substantially on radii and chords of said wheel, of a slide reciprocable with respect to said wheel, a tension dog pivotally connected with said slide and provided with a hook-shaped terminal portion adapted to engage the substantially radial surfaces of successive teeth upon said wheel, a compression dog pivotally connected with said slide and having a terminal portion adapted to enterinterdental spaces on said wheel and engage the substantial radial surfaces of said teeth at an angle such as to be retained in said spaces when under load, spring means urging the said terminal portions of said dogs into the interdental spaces of the wheel, cam means connected with each of said dogs and' 'n-ovided with a cam surface of predetermined contour and a pin adjustably guided with respect to the path of movement of said slide to and from an operative position fol-interaction with the cam means connected with one of said dogs, said pin being adapted, 'when in its operative positionto interact with said cam means and, at predetermined points in the movement of said slide, to overcome said spring means to lift the said terminal portion of said last mentioned dog from interdental spaces of said wheel.

18 In a device of the character described, the combination with a wheel having teeth provided respectively with surfaces disposed substantially on radii and chords of said wheel, of a slide guided for reciprocatory movement with respectto said wheel, a dog pivotally connected with said slide and provided with a terminal portion adapted to enter interdental spaces of said wheel and to eng the substantially radial faces of success ve teeth thereon, said teeth being formed to retain said dog in said spaces when said dog is under pressure, a spring urging said dog toward said wheel, a cam connected with said dog, a cam follower guided. for adjustment to and from an op erative position for interaction with said cam and mounted for resilient yielding from said position in opposition to a pressure exceeding that of said spring, said cam surface and cam follower being adapted for interaction in predetermined positions of movement of said slide to subject said dog to a force tending to withdraw it from the interdental spaces of said wheel, whereby said dog will disengage itself from said wheel when relieved of load and will not again engage said wheel during the said interaction of said cam and cam follower.

19. In a device of the character described, the combination with a load-sumaorting element guided for vertical reci n'ocation, of a toothed wheel journalcd for rotation adjacent said clement and provided with a link connection therewith and a slide reciprocable with reference to the wheel and provided with tension and compression members formed respectively for interaction with teeth on the upper and lower peripheral portions of said wheel.

20. In a device of the character described, the combination with a load supporting element guided for vertical reciprocation, of a toothed wheel adjacent said element and linked thereto, a slide reciprocable with reference to said wheel, closely adjacent pivotv pins mounted in said slide, dogs fulcrumed respectively on said pins and formed to extend arcuately about said wheel at substantially diametrically opposite points thereon, one of said dogs comprising a C()111-"' pression member andthe other of said dogs being provided with a hook and comprising a tension member, spring means urging said dogs to operative engagement with said wheel, a cross-head adjustable substantially in the path of movement of said slide, arms pivoted to'the cross-head and provided with pins adapted in one position of the cross head to project in the path of movement of portions of said dogs, said portions being pr vided with cam surfaces adapted for in teraction with said pins, means for nor mally guiding said pins to define a minimum separation therefor, spring means normall maintaining said pins in operative contact with said guiding means and adapted to exert thereon a force greater than that exerted by the spring means acting on the dogs and transmitted through said cam surfaces to said pins, said cam surfaces being formed to interact with said pins at predetermined points in the movement of said slide when said cross-head is adjusted to the said operative position whereby to se lectively lift said dogs from engagement with said wheel to permit the backward rotation thereof.

21. In a device of the character described, the combination with a toothed wheel and a slide reciprocable with reference thereto, of a dog pivotally connected with said slide and movable therewith and adapted for intcraction with the teeth of said wheel, a cam member connected with the dog, a ca1n-f0llower mounting adjustable between operative and retracted positions, a cam follower yieldably supported from said mounting and adapted, when said mounting is in its operative position, to engage operatively the cam surface on said dog at a predeterllt mined point in the movement of said dog with said slide, a spring normally pressing said dog toward said wheel, and a spring opposing the yielding movement of said cam follower and adapted normally to overcome the force of said first mentioned spring, the teeth of said wheel being formed to retain said dog under load whereby to prevent the dog from yielding under the pressure of said last mentioned springs until the load on said dog is relieved following the period of said interaction.

22. In a device of the character described, a load supporting element comprising a member guided for reciprocation and provided with a central opening, a plunger adjustable axially and rotatable in said opening and provided with peripheral grooves and-a latch member slidable transversely of said first mentioned member and adapted for engagement with one of the. grooves of said plunger.

In a device of the character described, a vWork supporting element comprising in combination a pair of telescopically adj ustable members adapted for relative reciprocation and-rotation, the innermost of said members being peripherally grooved at axially spaced intervals, and a latch device supported from the outer of said members and adjustable transversely thereof, said latch device being receivable in the grooves of the innermost member and being provided with an arcuate notch adapted to receive the central portion of said member for the support thereof from the outermost member While permitting relative rotation between said members.

24. In a device of the character described, the combination With a horizontal frame providing a rectilinearguideway and an oscillatory handle in pivotal connection with said frame at a point remote from said gnideway, of a handle operated load supporting element vertically movable in said guidcway, and motion transmitting connections operative between said handle and said element and adapted to actuate said element in a given direction upon the oscillation of said handle in either direction.

In a device of the character described, the combination with a horizontal frame providing a rectilinear upright guideway and an oscillatory handle in pivotal connection with said frame at a point remote from said guideway, of a handle operated load supporting element reciproeable in said gnideway, motion transmitting connections operative between said handle and said element including a toothed member connected with said element and a pair of pawls con nectednvith said handle adapted upon oscillation of said handle in opposite directions to interact respectively with said toothed member to produce unidirectional movement of said element, and means for controlling said motion transmitting connections whereby selectively to actuate said element either upwardly or downwardly in said guideway.

MARTIN L. HEINEKE. 

